Mutations affecting regulation of cobinamide biosynthesis in Salmonella typhimurium

D. I. Andersson, J. R. Roth

Research output: Contribution to journalArticlepeer-review

29 Scopus citations


Transcription of the genes for cobalamin biosynthesis is reduced during aerobic growth. We isolated and characterized mutants that showed a 2- to 90-fold increase in aerobic expression of the cobinamide biosynthesis (CobI) genes, depending on the particular mutation and growth condition. Four different classes of mutations were characterized. All mutations (CobRI) through CobRIV) were cis-acting, dominant mutations that mapped near the promoter end of the CobI operon. Two of these classes of mutations (III and IV) caused an increase in anaerobic as well as aerobic transcription of the CobII and CobIII operons; this led to increased biosynthesis of cobalamin under anaerobic growth conditions. A recessive mutation (cobF) mapping far from the CobI operon increased anaerobic CobI operon expression by about fourfold.

Original languageEnglish (US)
Pages (from-to)6726-6733
Number of pages8
JournalJournal of Bacteriology
Issue number12
StatePublished - 1989
Externally publishedYes

ASJC Scopus subject areas

  • Applied Microbiology and Biotechnology
  • Immunology


Dive into the research topics of 'Mutations affecting regulation of cobinamide biosynthesis in Salmonella typhimurium'. Together they form a unique fingerprint.

Cite this